Silo having a plurality of bins therein



Nov. 7, 1967 H. JERU 3,350,995

SILO HAVING A PLURALITY OF BINS THEREIN Filed Oct. 22, 1965 2 Sheets-Sheet l Nov. 7, 1967 JERU sILo HAVING A PLURALITY OF BINS THEREIN 2 Sheets-Sheet 2 Filed Oct. 22, 1965 /9 Try:

United States Patent Oflfice 3,350,995 Patented Nov. 7, 1967 5 Claims. b1. 9s-5s ABSTRACT OF THE DISCLOSURE A battery of silo bins formed by dividing the annular space between two coaxial cylindrical walls into separate compartments by means of radial partition walls of helical shape so as to prevent arching of the ensilaged material.

The present invention relates to arrangements capable of facilitating the emptying of silos and of reducing the pressures to which the latter are subjected by the effect of the ensilaged material.

It is known that the emptying of silos is sometimes prevented, at least temporarily, by the formation of arches of the ensilaged material against the walls of the silo, accompanied by the formation of a discharge arch or dome in the centre of the material itself.

These temporary stoppages generally terminate in an abrupt breaking-up of the discharge dome, followed by the fall of all the ensilaged material and by a considerable increase in pressure against the walls of the silo, due to the dynamic effect of the fall.

The clogging of the ensilaged materials, sometimes due to unforeseen causes, such as an excess of humidity, assists this effect of intermittent emptying, to the detriment of the good performance of the construction, since the abovementioned dynamic eflect is far from being always taken into consideration in the dimensioning of the walls of the silo.

Means exist which are intended to palliate the drawbacks mentioned above, means such as for example emptying chimneys, the function of which consists of effecting the emptying from the upper layers of ensilaged material, which has the advantage of permitting partial emptying without setting all the interposed mass in movement.

Apart from the complexity of such a device, this palliative has the disadvantage of leaving the lower layers of stored material in the silo for an unduly long and theoretically unlimited period, unless complete systematic emptyings of the silo are carried out at regular intervals.

Another known expedient for overcoming the abovementioned drawbacks, consists in forming the silo bins with inclined partition walls, as described for instance in the German Patent No. 543,417, granted on Feb. 5, 1932, and the German Patent No. 666,564, granted on Oct. 24, 1938. Such silos are conducive to a waste of space, or to unequal capacities of bins, or to bins which are placed on top of each other, with service openings situated at a ditterent height for each bin.

An object of the present invention is to provide a bank of silo bins formed with inclined partition walls, having the same height and placed level with each other, and capable of being housed within a vertical peripheral wall while using all the space available Within said wall.

The invention also contemplates a device capable of facilitating the aeration of the ensilaged material and of etiectively preventing it from deteriorating or clogging.

According to the invention, there is provided a battery of silo bins having inclined partition walls and distributed around an upright member, and wherein the average lines of fall of the ensilaged material within said bins define winding curves rotating in the same direction about said upright member.

Such bins require curved partition walls of a relatively complex shape, and the invention has, as another object, specific methods of construction for producing such partition walls easily and economically, and even for taking advantage of their shape in order to increase their structural strength.

These and other advantages of the invention will be brought out in the description which follows below, of one embodiment thereof, chosen by way of example and illustrated by the accompanying drawings.

In these drawings:

FIG. 1 relates to a battery of three silo bins of a known yp FIG. 2 refers to a battery of inclined bins of a known type occupying as a whole a volume defined by four vertical walls, parallel in pairs;

FIG. 3 shows diagrammatically a perspective view of a bank or battery of silo bins according to the invention;

FIG. 4 is a cross-section in plan taken along line IVIV in FIG. 3;

FIG. 5 is a cross-section FIG. 3.

Referring now to FIG. 1, there is seen a battery of three silo bins or cells joined side by side, of prismatic shape with parallel inclined rectilinear axes. There has been indicated in this drawing the decomposition of a force OM, representing a certain weight of ensilaged material, into two vectors, namely a force OR representing the reaction on the partition of silo 1, and OP representing taken along line V-V in the reaction absorbed by the lower layers or material.

The vector OR is inclined to the normal to the partition 1 because of friction.

Contrary to what takes place in the case of vertical partitions, it is seen that the vector OR comprises a large vertical component and that the effect of hydrostatic pressure, represented by the vector OP, is reduced accordingly. This has the result of reducing the internal pressures in the lower layers, and especially in the vicinity of the emptying orifices 2.

On the other hand, if the cell 3 is considered, for example, the pressure of grain or ore is much higher on the partition 1 than on the opposite partition 4, which considerably reduces the possibility of formation of arches in the ensilaged material.

In addition, the inclined partitions which directly support the weight of the material are more heavily loaded in the upper zones of the cell than would be the case with vertical partitions, but the charge per unit of surface increases less rapidly with the depth than in the case of the vertical cells. This results in a better utilization of the construction material. It is known in fact that in the case of vertical cells, the thickness of the partitions in the upper zones is greater than would be required for resisting the pressures.

There may be seen in FIG. 1 that cells 3 require more space area than vertical cells of equal capacity. They also require additional columns 5.

There is shown in FIG. 2 inclined cells of another known type, which present from the exterior the aspect of a battery of vertical cells. The inclined cells, housed in a vertical parallelepiped have unequal capacities, and some of them require special provisions for loading and discharging, in the shape of chutes 9 and 12.

As mentioned, in a silo according to the invention, the average lines of fall in the bins define win-ding curves about an upright. These curves may be helices, for ex ample helices with a circular projection, which enables a series of bins to be housed in a circular cylindrical wall and thereby to form a compact unit.

Thus, there is seen from FIGS. 3 and 4 a battery of six cells shaped from an outer circular cylindrical wall with a vertical axis, a coaxial upright and service shaft in the form of an internal cylinder 15, and six partitions 16.

As also appears from FIG. 3, the outer circular cylindrical wall is fitted at the bottom with a hopper wall converging downwardly toward and extending to the service shaft 15, for leading thereto the ensilaged material from each of the six cells, in a manner well known in the art.

Each of these partitions rests on the cylinders 14 and 15 on two respective series of supports, distributed along two respective average lines of support 17 and 18, defining helices of the same pitch on cylinders 14 and 15.

In the form of embodiment described here, the partition 16 is not formed by a true hellcoidal surface, since such a shape is difiicult to produce in practice. The partition 16 can conveniently be formed by fiat sheets 19 made of any convenient material, e.g. steel, and capable of being elastically deformed in order to be supported on and assembled by a convenient means, e.g. welding to said series of supports, which may consist of angle sections 20, 21, fixed to cylinders 14 and 15 along helices 17 and 18.

Wedge-shaped packing pieces 20a (shown in FIG. but omitted from FIG. 3) may be sandwiched between sheets 29 and one of said angle-sections 20, 21, or both of them, to provide for sheets 29 a series of supports arranged in steps, cooperating with flanges 29a for forming ridges on the partition wall faces.

It will be observed that the helices 17 are less inclined to the vertical than the helices 18. In practice, the anglesection supports such as 20, 21 can be taken as similar, over the length of a sheet 19, to two rectilinear but not coplanar supports. Consequently, the average outlines of the two opposite edges of contact of a sheet 19 with supports 20, 21, define two non-coplanar portions of straight lines when plate 19 is fixed on supports 20, 21. It is thus found that the elastic deformation of the sheets 16, intended to ensure their contact with the supports 20 and 21, produces in these sheets a double curvature, as for a hyperbolic paraboloid, and this has the result of inducing a large increase in strength of these sheets.

FIG. 3 shows the average line of fall M of the ensilaged material for one of the bins. Line M defines a winding curve about upright 15, and may be assumed to coincide with the line defined by the centers of gravity of plan sectional areas of the bin at various levels.

The angle-sections 20, 21 may be arranged in steps if so desired, or along broken lines as described in applicants co-pending application for Improvements in Methods of Construction. As mentioned, sheets 19 may have flanges 19a for forming ridges on the partition wall faces, as may be seen from FIG. 5, and for producing in the ensilaged material passages having less resistance to air so as to facilitate aeration of the material.

There can be seen in FIG. 4 one of these passages, referenced by 22, and shown in chain-dotted lines. On this same figure, the reference 23 designates an air-supply pipe placed in the cylinder 15 and provided with nozzles 24 so as to blow air into the passages 22. Two suction pipes 25 and 26 provided with orifices protected by hoods 27 draw-in air and force it to pass through the whole ensilaged mass, following the paths indicated by the arrows 28.

The outer wall 14 is stiffened on its outer face by helicoidal angle-sections 29 arranged normally to the angleiron supports 19. In fact, as indicated above, a large part of the weight of ensilaged material is directly applied to the inclined partitions and is transmitted to the ground through the intermediary of the outer vertical walls. In consequence, it may be advisable to stiffen these vertical walls in order to prevent them from buckling.

It will of course be understood that the forms of embodiment which have been described by Way of examples do not comprise any limitative character. They may form the object of various alternatives, without thereby departing from the scope of the invention, and they are applicable to any appropriate constructional material: metal, concrete, wood or the like, for the purpose of storage of any materials, grain, ore, chemical products or the like. The sheets 19 shown in FIG. 3 may thus be used to form a shuttering or falsework for building reinforced concrete inclined partition walls.

What I claim is:

1. A silo having a plurality of bins, the silo consist ing of one outer vertical cylindrical wall, one inner cylindrical wall disposed inside said outer wall coaxially thereto, said inner wall defining within itself one service shaft, said inner and outer walls defining between them an annular space, a hopper wall fitted to the bottom of said outer wall and converging downwardly toward and extending to said inner wall and closing said annular space and leading by gravity to said service shaft a material ensilaged in said annular space for removal of said material from the silo, and helically shaped partitions dividing said annular space into bins.

2. A silo according to claim 1, having supports provided on opposite faces of said inner and outer walls and defining on said walls respective helices of equal pitch, wherein said partitions consist of sheets contacting along two of their opposite edges said supports and fixed thereto.

3. A silo according to claim 1, wherein said supports are arranged in steps on at least one of said opposite faces, while said sheets are formed with a flange along one edge, said flanges cooperating with said step formation to produce ridges on the partition wall faces.

4. A silo according to claim 3, having nozzles for injecting air within a bin along a partition wall face parallel to said ridges.

5. A silo according to claim 4, having air orifices disposed within said bin.

References Cited UNITED STATES PATENTS 171,290 12/1875 Lassen 98-55 1,194,118 8/1916 Adolf 34-147 2,226,535 12/1940 Payne 34-147 X 2,669,540 2/1954 Weinrich 34147 X ROBERT A. OLEARY, Primary Examiner.

M. A. ANTONAKAS, Assistant Examiner, 

1. A SILO HAVING A PLURALITY OF BINS, THE SILO CONSISTING OF ONE OUTER VERTICAL CYLINDRICAL WALL, ONE INNER CYLINDRICAL WALL DISPOSED INSIDE AND SAID OUTER WALL COAXIALLY THERETO, SAID INNER WALL DEFINING WITHIN ITSELF ONE SERVICE SHAFT, SAID INNER AND OUTER WALLS DEFINING BETWEEN THEM AN ANNULAR SPACE, A HOOPER WALL FITTED TO THE BOTTOM OF SAID OUTER WALL AND CONVERGING DOWNWARDLY TOWARD AND 